[A case of bronchiolitis with IgG4-positive plasma cells infiltration associated with Mikulicz's disease and autoimmune pancreatitis].

A 23-year-old Japanese man was admitted to our hospital because of dry cough and lacrimal gland swelling. Laboratory findings showed hypergammaglobulinemia (4859 mg/dl), hypocomplementemia (CH50 13 U/ml), and hyperamylasemia. CT revealed a marked swelling of the bilateral lacrimal glands, diffuse patchy infiltration in the bilateral lung fields, and enlargement of the whole pancreas. Gallium citrate scintigraphy showed abnormal accumulation in the bilateral lacrimal glands, submandibular glands, and both lung fields. Biopsy specimens from the salivary gland revealed dense lymphoplasmacytic infiltration and abundant IgG4-positive plasma cells. Furthermore, open lung biopsy showed a marked peribronchial lymphoplasmacytic and eosinophilic infiltration with IgG4-positive plasma cells. These findings fulfilled the criteria of Mikulicz's disease and autoimmune pancreatitis, and support the recently proposed concept of IgG4-related systemic disease.

Activation of peroxisome proliferator-activated receptor gamma inhibits TNF-alpha-mediated osteoclast differentiation in human peripheral monocytes in part via suppression of monocyte chemoattractant protein-1 expression.

Tumor necrosis factor-alpha (TNF-alpha) plays critical roles in bone resorption at the site of inflammatory joints. The aim of this study is to evaluate the effect of peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonists, a new class of anti-inflammatory compounds, on TNF-alpha-mediated osteoclastogenesis in human monocytes. Human monocytes were differentiated into osteoclasts in the presence of TNF-alpha and macrophage colony-stimulating factor. Tartrate-resistant acid phosphatase (TRAP) staining and a pit formation assay using dentin were used for the identification of activated osteoclasts. The protein and gene expressions of transcription factors were determined by immunofluorescence and real-time RT-PCR analysis, respectively. TNF-alpha-induced osteoclast generation from human peripheral monocytes in a dose-dependent manner, and the induction was not inhibited by osteoprotegerin, a decoy receptor for receptor activator of NF-kappaB ligand. The addition of PPAR-gamma agonists, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) or ciglitazone, to the culture resulted in a remarkably reduced number of generated osteoclasts. In addition, both agonists inhibited the protein and gene expressions of nuclear factor of activated T-cell isoform c1 (NFATc1), c-Fos, c-Jun and NF-kappaB p65, which are known to be associated with osteoclastogenesis. GW9662, an antagonist of PPAR-gamma, fully rescued ciglitazone-induced inhibition, but did not affect 15d-PGJ2-induced inhibition. Monocyte chemoattractant protein-1 (MCP-1), a CC chemokine related to osteoclastogenesis, was induced during TNF-alpha-mediated osteoclast differentiation, and the neutralizing antibody to MCP-1 reduced osteoclast formation by about 40%. 15d-PGJ2 and ciglitazone blocked the induction of MCP-1 by TNF-alpha. Moreover, the addition of MCP-1 rescued the inhibition of TRAP-positive multinucleated cell (TRAP-MNCs) formation by 15d-PGJ2 and ciglitazone, although generated TRAP-MNCs had no capacity to resorb dentin slices. Our data demonstrate that 15d-PGJ2 and ciglitazone down-regulate TNF-alpha-mediated osteoclast differentiation in human cells, in part via suppression of the action of MCP-1. These PPAR-gamma agonists may be a promising therapeutic application for rheumatoid arthritis and inflammatory bone-resorbing diseases.

Detection of primary and metastatic lesions by [18F]fluoro-2-deoxy-D-glucose PET in a patient with thymic carcinoid.

We present a case of thymic carcinoid, in which primary and metastatic lesions of lymph nodes and bones could be detected by [(18)F]fluoro-2-deoxy-D-glucose (FDG)-PET, but not by (123)I-meta-iodobenzylguanidine ((123)I-MIBG) SPECT, or by (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scintigraphy. FDG-PET may be a useful tool for managing thymic carcinoids in patients with negative results on (123)I-MIBG SPECT or (99m)Tc-MDP imaging.

Interleukin-10 inhibits RANKL-mediated expression of NFATc1 in part via suppression of c-Fos and c-Jun in RAW264.7 cells and mouse bone marrow cells.

Interleukin-10 (IL-10), an anti-inflammatory cytokine, has been shown to inhibit osteoclast formation and bone resorption in rat and mouse systems. However, the precise intracellular mechanism(s) of this action remains unclear. The aim of this study was to clarify the role of IL-10 in the regulation of critical transcription factors involved in osteoclastogenesis. A RAW264.7 macrophage cell line, which constitutively expressed IL-10 receptor, was differentiated to osteoclasts with stimulation of receptor activator of nuclear factor kappaB ligand (RANKL). IL-10 inhibited the RANKL-induced osteoclastogenesis. IL-10 potently reduced the RANKL-induced expression of NFATc1, c-Jun and c-Fos, which are known to be essential for osteoclastogenesis, in time- and dose-dependent manners. The IL-10-induced inhibition of these transcription factors was observed in the system of mouse bone marrow precursors. Besides these transcription factors, IL-10 also decreased the RANKL-induced expression of NF-kappaB p50 and phosphorylation of JNK. To determine which signaling was critical for the IL-10 effect, we examined the effect of overexpression of NFATc1, c-Fos, and c-Jun on the IL-10-induced inhibition of osteoclastogenesis. As expected, overexpression of NFATc1 abrogated the IL-10-induced inhibition of osteoclastogenesis. Interestingly, overexpression of either c-Fos or c-Jun partially rescued the reduction of RANKL-induced expression of NFATc1 and osteoclastogenesis by IL-10. These data suggest that IL-10 may down-regulate osteoclastogenesis mainly through inhibition of the expression of NFATc1, c-Fos and c-Jun. These findings provide new insight into the inhibitory action of IL-10 on RANKL-mediated osteoclastogenesis.

Isoproterenol suppresses cytokine-induced RANTES secretion in human lung epithelial cells through the inhibition of c-jun N-terminal kinase pathway.

It has been reported that beta2-agonists may potentially exert some anti-inflammatory action in addition to bronchodilation that may contribute to their beneficial effects on asthma control. Bronchial epithelial cells are well known to respond to a range of stimuli by producing various biologically active mediators that can influence airway inflammation. RANTES (regulated on activation, normal T cells expressed and secreted) plays an important role in the pathophysiology of airway inflammation of asthmatics through its chemotactic activity for eosinophils. In this study, the authors investigated whether cytokine-induced RANTES release from BEAS-2B human bronchial epithelial cells could be modulated by beta-agonist isoproterenol (ISO). The possible involvement of c-jun N-terminal kinase (JNK) pathway was also studied. Combination of tumor necrosis factor-alpha and interleukin-1beta (cytokine mix) increased RANTES release from BEAS-2B cells and stimulated JNK activity. Similar to JNK inhibitor SP600125, ISO inhibited not only the production of RANTES but also the activation of JNK pathway in cytokine mix-stimulated BEAS-2B cells. The effect of ISO was mediated by the beta2-adrenoceptor, since it was blocked by ICI 118,551, a selective beta2-receptor antagonist, but not by atenolol, a selective beta1-receptor antagonist. Adenylyl cyclase activator forskolin reproduced the effects of ISO. Isoproterenol was found to inhibit the release of RANTES from the human bronchial epithelial cells, at least in part, through the inhibition of JNK signaling pathway.

Ionizing radiation suppresses FAP-1 mRNA level in A549 cells via p53 activation.

Ionizing radiation (IR) is known to upregulate cell surface Fas through p53 activation in various cells. However, the signaling pathway intermediating between p53 activation and cell surface Fas upregulation remains to be elucidated. Recently, Fas-associated phosphatase-1 (FAP-1) has been reported to associate with Fas and inhibit cell surface Fas expression. We evaluated the expression of FAP-1 mRNA following IR in A549 cells. Ionizing radiation inhibited the expression of FAP-1 mRNA. Pretreatment with p53 inhibitor pifithrin alpha cancelled the IR-induced downregulation of FAP-1 mRNA. These results suggest that IR-induced p53 activation may upregulate cell surface Fas via the down-modulation of FAP-1.

Enzymatic and biochemical properties of a novel human serine dehydratase isoform.

A cDNA clone similar to human serine dehydratase (SDH) is deposited in the GenBank/EMBL databases, but its structural and functional bases remain unknown. Despite the occurrence of mRNA, the expected protein level was found to be low in cultured cells. To learn about physicochemical properties of the protein, we expressed the cDNA in Escherichia coli, and compared the expressed protein with that of a hepatic SDH. The purified protein showed l-serine and l-threonine dehydratase activity, demonstrating to be an isoform of SDH. However, their Km and Vmax constants were different in a range of two-order. Removal of Pro128 from the hepatic SDH consisting of 328 residues, which is missing in the corresponding position of the isoform consisting of 329 residues, significantly changed the Michaelis constants and Kd value for pyridoxal 5'-phosphate, whereas addition of a proline residue to the isoform was without effect. These findings suggest the difference in the structures of the active sites of the two enzymes. Another striking feature was that the expressed level of the isoform in E. coli was 7-fold lower than that of the hepatic SDH. Substitution of Val for Leu287 in the isoform dramatically increased the protein level. The high yield of the mutated isoform was also confirmed by the in vitro transcription and translation experiment. The poor expression of the isoform could be explained by the more stable secondary structure of the mRNA than that of the hepatic SDH mRNA. The present findings may provide a clue as to why the protein level in cultured cells is low.

Doxorubicin induces expression of multidrug resistance-associated protein 1 in human small cell lung cancer cell lines by the c-jun N-terminal kinase pathway.

Multidrug resistance (MDR) is a major impediment to successful chemotherapy for lung cancer. Overexpression of multidrug resistance-associated protein 1 (MRP1) appears to be involved in MDR development in lung cancer cells. A number of chemotherapeutic agents including doxorubicin (DOX) were reported to induce MRP1 expression in human lung cancer cells. In our study, we investigated the mechanism by which DOX induces MRP1 expression in human small cell lung cancer (SCLC) cell lines, GLC4 and NCI-H82. These cells expressed MRP1 protein at low levels and were sensitive to DOX. Doxorubicin at 50 nM induced a marked increase in MRP1 expression in 24 hr, and stimulated c-jun N-terminal kinase (JNK) activity. Treatment with a JNK inhibitor, SP600125, significantly inhibited MRP1 induction. Furthermore, transfection with JNK1 and JNK2 antisense oligonucleotides markedly inhibited DOX-induced MRP1 expression. Chromatin immunoprecipitation assays revealed an enhanced recruitment of phosphorylated c-jun to the MRP1 promoter containing the AP-1 site upon DOX stimulation, which was inhibited by pretreatment with SP600125. Surprisingly, GLC4 cells exposed to DOX for 24 hr maintained increased MRP1 expression and resistance to DOX for at least 3 weeks. Pretreatment with SP600125 before DOX stimulation blocked the appearance of the MDR phenotype as well as MRP1 induction in GLC4 cells. These findings suggest that JNK activation may play an essential role for the induction of MRP1 protein in human SCLC cells by chemotherapeutic agents and that combined treatment of a JNK inhibitor with anticancer drugs may prevent the development of MDR by the abrogation of MRP1 induction.

Interleukin-4 inhibits RANKL-induced expression of NFATc1 and c-Fos: a possible mechanism for downregulation of osteoclastogenesis.

Interleukin-4 (IL-4), an anti-inflammatory cytokine, has been shown to inhibit osteoclast differentiation. Therefore, this cytokine is considered to be a promising therapeutic applicant for bone-resorbing diseases such as rheumatoid arthritis (RA). Recently NFATc1, a transcription factor, has been shown to play critical roles in osteoclastogenesis. The aim of this study was to clarify the role of IL-4 on the intracellular signaling of NFATc1. A RAW264.7 monocyte/macrophage cell line and murine bone marrow precursors were differentiated into osteoclasts in the presence of receptor activator of nuclear factor kappaB ligand (RANKL) and/or macrophage colony-stimulating factor. Tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine were used for the identification of activated osteoclasts. The protein expression of IL-4 receptor, NFATc1, and c-Fos was determined by Western blot analysis. In addition, the gene expression of NFATc1 and c-Fos was determined by reverse transcription and polymerase chain reaction. The IL-4 receptor was constitutively expressed in RAW264.7 cells. RANKL induced osteoclast generation, as determined by TRAP staining and pit assay. IL-4 inhibited RANKL-induced osteoclastogenesis at low concentrations of 10ng/ml and more. Interestingly, IL-4 potently inhibited RANKL-induced expression of NFATc1 at mRNA level. Furthermore, IL-4 inhibited c-Fos expression, which is shown to be responsible for NFATc1 expression, in time- and dose-dependent manners. In addition, IL-4 inhibited the RANKL-induced expression of NFATc1 and c-Fos in murine bone marrow cells. Thus, we suggest that IL-4 may downregulate osteoclastogenesis in part through inhibition of the expression of transcription factors, NFATc1 and c-Fos. These findings provide new insight into development of new medication for osteoporosis and RA.

[Marked improvement of Lambert-Eaton myasthenic syndrome resulting from treatment for small cell lung carcinoma].

A 68-year-old man was admitted to our hospital because of muscle weakness. A complete medical examination led to a diagnosis of small cell lung carcinoma (SCLC) with Lambert-Eaton myasthenic syndrome (LEMS) and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Four courses of chemotherapy (carboplatin + etoposide) and one of radiotherapy with a total dose of 45 Gy to the mediastinum were performed and resulted in a partial response in the SCLC. After the second course of chemotherapy, the serum level of antivoltage-gated Ca2+ channel (VGCC) antibody decreased from 190 pg/ml to 120 pg/ml. Marked improvement of the muscle weakness was recognized only after 3 courses of chemotherapy. The patient, who had had difficulty in standing, recovered enough to be able to climb stairs after 4 courses of chemotherapy. Marked improvement of LEMS was achieved by treatment for small cell lung carcinoma.

Hydrogen peroxide induces upregulation of Fas in human airway epithelial cells via the activation of PARP-p53 pathway.

Fas mediates apoptosis following binding with Fas ligand. Fas is expressed in human airway epithelial cells and has a critical role in the pathophysiology of various pulmonary disorders. Hydrogen peroxide (H(2)O(2)) is an important mediator of airway epithelial injury. In this context, we hypothesized that H(2)O(2) would increase the expression of cell surface Fas in human airway epithelial cells. To test this hypothesis, the modulation of Fas expression with H(2)O(2) was assessed in normal human bronchial epithelial cells and A549 cells. The majority of Fas was cytoplasmic in both cell types without any stimulation. Hydrogen peroxide significantly increased Fas in the plasma membrane fraction, while decreasing Fas in the cytoplasmic fraction. Incubation with an agonistic antibody for Fas induced apoptosis in H(2)O(2)-treated cells in proportion to the level of surface Fas expression on those cells. Inhibitors of poly(ADP-ribose) polymerase abrogated the H(2)O(2)-induced Fas translocation to the plasma membrane and p53 activation. Expression of dominant-negative p53 also inhibited the Fas translocation induced by H(2)O(2) in A549 cells. These results indicate that H(2)O(2) induces Fas upregulation by promoting cytoplasmic transport of Fas to the cell surface in human airway epithelial cells, and that the activation of the poly(ADP-ribose) polymerase-p53 pathway may be involved in this mechanism.

Inhibition of proteasome activity is involved in cobalt-induced apoptosis of human alveolar macrophages.

Inhalation of particulate cobalt has been known to induce interstitial lung disease. There is growing evidence that apoptosis plays a crucial role in physiological and pathological settings and that the ubiquitin-proteasome system is involved in the regulation of apoptosis. Cadmium, the same transitional heavy metal as cobalt, has been reported to accumulate ubiquitinated proteins in neuronal cells. On the basis of these findings, we hypothesized that cobalt would induce apoptosis in the lung by disturbance of the ubiquitin-proteasome pathway. To evaluate this, we exposed U-937 cells and human alveolar macrophages (AMs) to cobalt chloride (CoCl(2)) and examined their apoptosis by DNA fragmentation assay, 4',6-diamidino-2'-phenylindol dihydrochloride staining, and Western blot analysis. CoCl(2) induced apoptosis and accumulated ubiquitinated proteins. Exposure to CoCl(2) inhibited proteasome activity in U-937 cells. Cobalt-induced apoptosis was mediated via mitochondrial pathway because CoCl(2) released cytochrome c from mitochondria. These results suggest that cobalt-induced apoptosis of AMs may be one of the mechanisms for cobalt-induced lung injury and that the accumulation of ubiquitinated proteins might be involved in this apoptotic process.

Leukotriene C4 synthase promoter polymorphism in Japanese patients with aspirin-induced asthma.

BACKGROUND: The A to C transversion in the promoter region of the gene encoding leukotriene C4 synthase (LTC4S) is proposed to be associated with the development of aspirin-induced asthma (AIA). OBJECTIVE: We investigated the frequency of the polymorphism in Japanese population and its association with clinical characteristics and cysteinyl leukotriene production. METHODS: Genotyping of LTC4S gene promoter was performed on 60 patients with AIA, 100 patients with aspirin-tolerant asthma (ATA), and 110 control subjects. We assessed the basal levels of urinary LTE4, the increment of urinary LTE4 on venous aspirin challenge, and LTC4S activity in peripheral blood eosinophils. RESULTS: The frequency of the variant C allele was significantly higher in patients with AIA (frequency of allele [q] = 0.192) than in patients with ATA (q = 0.110, P =.042). Variant C-allelic carriers experienced asthma at a significantly younger age (31.8 +/- 2.9 years [mean +/- SEM]) than wild-type A homozygotes (41.3 +/- 2.2 years, P =.007). Basal levels of LTE4 and the increment of urinary LTE4 on venous aspirin challenge did not show a difference between wild-type A homozygotes and variant C-allelic carriers. There was no relationship between the polymorphism and the LTC4S activity in eosinophils, although LTC4S activities were significantly higher in patients with AIA than in patients with ATA. CONCLUSION: Our findings reveal the lack of functionality of the polymorphism in the LTC4S gene, whereas this polymorphism might have some effect on the development of AIA, probably in linkage disequilibrium with another causatively important mutation.